package code.android.MiracleWalker.view;

import android.content.Context;
import android.graphics.Camera;
import android.graphics.Matrix;
import android.util.AttributeSet;
import android.view.View;
import android.view.animation.Transformation;
import android.widget.Gallery;
import android.widget.ImageView;

public class CoverFlow extends Gallery
{
	private Camera mCamera = new Camera();
	
	private int mMaxRotationAngle = 80;
	
	private int mMaxZoom = -120;
	
	private int mCoveflowCenter;
	
	public CoverFlow(Context context) 
	{
		super(context);
		this.setStaticTransformationsEnabled( true );
	}
	
	public CoverFlow(Context context, AttributeSet attrs)
	{
		super(context, attrs);
		this.setStaticTransformationsEnabled(true);
	}

	public CoverFlow(Context context, AttributeSet attrs, int defStyle) 
	{
		super(context, attrs, defStyle);
		this.setStaticTransformationsEnabled(true);
	}
	
	public int getMaxRotationAngle() 
	{
		return mMaxRotationAngle;
	}

	public void setMaxRotationAngle(int maxRotationAngle) 
	{
		mMaxRotationAngle = maxRotationAngle;
	}

	public int getMaxZoom()
	{
		return mMaxZoom;
	}

	public void setMaxZoom(int maxZoom) 
	{
		mMaxZoom = maxZoom;
	}

	private int getCenterOfCoverflow() 
	{
		return (getWidth() - getPaddingLeft() - getPaddingRight()) / 2 + getPaddingLeft();
	}

	private static int getCenterOfView(View view) 
	{
		return view.getLeft() + view.getWidth() / 2;
	}

	protected boolean getChildStaticTransformation(View child, Transformation t) 
	{
		final int childCenter = getCenterOfView(child);
		final int childWidth = child.getWidth();
		int rotationAngle = 0;

		t.clear();
		t.setTransformationType(Transformation.TYPE_MATRIX);

		if (childCenter == mCoveflowCenter) 
		{
			transformImageBitmap((ImageView) child, t, 0);
		} 
		else 
		{
			rotationAngle = (int) (((float) (mCoveflowCenter - childCenter) / childWidth) * mMaxRotationAngle);
			
			if (Math.abs(rotationAngle) > mMaxRotationAngle) 
			{
				rotationAngle = (rotationAngle < 0) ? -mMaxRotationAngle : mMaxRotationAngle;
			}
			transformImageBitmap((ImageView) child, t, rotationAngle);
		}

		return true;
	}

	protected void onSizeChanged(int w, int h, int oldw, int oldh)
	{
		mCoveflowCenter = getCenterOfCoverflow();
		super.onSizeChanged(w, h, oldw, oldh);
	}

	private void transformImageBitmap(ImageView child, Transformation t, int rotationAngle) 
	{
		mCamera.save();
		final Matrix imageMatrix = t.getMatrix();
		final int imageHeight = child.getLayoutParams().height;
		final int imageWidth = child.getLayoutParams().width;
		final int rotation = Math.abs(rotationAngle);

		mCamera.translate(0.0f, 0.0f, 100.0f);

		// As the angle of the view gets less, zoom in
		if (rotation < mMaxRotationAngle) {
			float zoomAmount = (float) (mMaxZoom + (rotation * 1.5));
			mCamera.translate(0.0f, 0.0f, zoomAmount);
		}

		mCamera.rotateY(rotationAngle);
		mCamera.getMatrix(imageMatrix);
		imageMatrix.preTranslate(-(imageWidth / 2), -(imageHeight / 2));
		imageMatrix.postTranslate((imageWidth / 2), (imageHeight / 2));
		mCamera.restore();
	}

}
